The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Generally, a vehicle is provided with a transmission which receives power generated from an engine to control a driving speed of a vehicle. The transmission is classified into a manual transmission which is controlled by a driver and an automatic transmission which is automatically controlled based on a driving speed of a vehicle.
The automatic transmission allows a shift controller to drive a plurality of solenoid valves based on a driving speed of the vehicle, an open value of a throttle valve, and general detection conditions so as to control an oil pressure, such that a transmission gear of a target gear stage is operated to perform the automatic shift.
When the driver operates the accelerator pedal, if the operation amount of the accelerator pedal is increased (for example, a situation that the vehicle is suddenly accelerated), the torque transmitted to a wheel through a kick down shift) is increased, accordingly the acceleration of the vehicle is increased.
According to the conventional art, the control hydraulic pressure of the clutch is determined based on the engine torque. If the accelerator pedal operation amount is increased, since the engine torque is also increased, the driver may control the acceleration and the shift responsiveness of the vehicle depending on the accelerator pedal operation amount.
On the other hand, recently, the engine including a turbocharger is widely supplied. In the engine including the turbocharger, when accelerating the vehicle in the low-speed range, the torque increasing is delayed by a turbo lag. Accordingly, regardless of the operation amount and the operation speed of the accelerator pedal, since the engine torque is small, the acceleration and the shift response speed of the vehicle may be delayed.